When I use my IM program on my blackberry, it sends information (buddy list) as text messages that don't show up in my message box... the only reason why I know it's there is because I put my sim in a regular phone and like 30 texts show up...

the only problem with this situation is that eventually my sim mail box will fill up and then I can't get my buddy list anymore for AIM...

I called tmobile customer service already and they can't figure it out... I've also rifled through all the folders on my black berry and can't find this mysterious text messages

Same thing happens to me. I had to replace my 7100t after the first one turned out to be a junker, and when I put my SIM into the new unit, all my IM conversations suddenly appeared as a zillion SMS messages. I've switched to Verichat, at this point, since I didn't like the idea of all those messages just sort of hanging out somewhere...